/Engine/Plugins/Runtime/nDisplay/Source/DisplayCluster/Public/IDisplayClusterCallbacks.h
Called in the end of the nD rendering chain, right before updating the backbuffer
class FDisplayClusterPostFrameRender_RenderThread : public TBaseMulticastDelegate_ThreeParams< void, FRHICommandListImmediate &, const IDisplayClusterViewportManagerProxy *, FViewport * >